Question

notches are carved on the tyres of vehicles because
1. to make the tyres look beautiful 2. to increase friction
3. to decrease friction 4. to raise the speed

Answer 1

To increase friction 

Answer 2

The answer is 2) to increase friction.

Notches are carved on the tyres of vehicle to increase friction. The more friction that a vehicle experiences, the more balance it will have. This will in turn prevent the vehicle from skidding or overturning, especially at curves. Friction is also helpful on wet roads as they tend to be slippery.